What is the recommended schedule and dosage for a rabies (inactivated rabies vaccine) booster dose in individuals who have previously completed a primary rabies vaccination series?

Rabies Booster Vaccination: When and How to Administer

Postexposure Boosters for Previously Vaccinated Individuals

If a previously vaccinated person is exposed to rabies, administer two 1.0 mL intramuscular doses in the deltoid muscle—one immediately (day 0) and one on day 3—without rabies immunoglobulin (RIG). 1, 2, 3

Key Points for Postexposure Management:

• Previously vaccinated means anyone who completed a recommended preexposure or postexposure series with HDCV, PCECV, or RVA, or has documented rabies virus neutralizing antibody titers 1, 2

• Never administer RIG to previously vaccinated individuals, as it may inhibit the rapid anamnestic antibody response that occurs after booster vaccination 2, 3

• Do not check antibody titers before giving boosters to previously vaccinated exposed persons—this delays treatment unnecessarily and no specific "protective" titer threshold is definitively established 2

• Always begin with thorough wound cleansing using soap and water, regardless of vaccination status 3, 4

Preexposure Booster Schedule Based on Risk Category

The timing of routine preexposure boosters depends entirely on occupational risk level:

Continuous Risk Category (Highest Risk):

• Who: Rabies laboratory workers handling live virus in research or vaccine production facilities 1
• When: Check serum antibody titers every 6 months 1
• Action: Give a booster dose if titer falls below complete neutralization at 1:5 dilution by RFFIT 1

Frequent Risk Category:

• Who: Diagnostic laboratory workers, veterinarians and staff in enzootic areas, animal control officers in enzootic areas, cavers/spelunkers, and anyone frequently handling bats anywhere in the world 1, 2
• When: Check serum antibody titers every 2 years 1
• Action: Give a single booster dose if titer is below complete neutralization at 1:5 dilution by RFFIT 1
• Alternative: The CDC allows giving a booster without testing in this group 2

Infrequent Risk Category:

• Who: Veterinarians and animal control officers in areas where rabies is uncommon/rare, international travelers who completed full preexposure series 1, 2
• When: No routine boosters required after completing primary vaccination series 1, 2
• Rationale: These individuals are considered immunologically primed and will mount rapid anamnestic response if exposed 1

Booster Dosing Regimens

Intramuscular Route (Standard):

• Dose: 1.0 mL administered in the deltoid area 1
• Products: HDCV or PCECV 1

Intradermal Route (Historical—No Longer Available in US):

• Dose: 0.1 mL intradermal over deltoid 1
• Note: ID preparations are no longer available in the United States as of 2008 1

Critical Pitfalls to Avoid

• Never use the gluteal region for vaccine administration due to risk of sciatic nerve injury 4

• Never administer vaccine and RIG in the same syringe, needle, or anatomical site 4

• Do not give RIG after day 7 of the vaccine series, as it may suppress active antibody production 5

• Avoid intradermal administration if the patient is taking chloroquine or mefloquine for malaria prophylaxis, as these drugs interfere with immune response—use intramuscular route instead 1

Special Populations

Immunosuppressed Individuals:

• May have suboptimal vaccine response and require consultation with public health officials 2, 3
• Check antibody titers after vaccination to confirm adequate response 3, 5
• If previously vaccinated and immunosuppressed: Consider giving the full 5-dose series rather than the 2-dose regimen, with mandatory serologic testing afterward 5

Interrupted Vaccine Series:

• Do not restart the series—simply resume from where you left off 5
• Delays of a few days are acceptable; longer interruptions may require antibody testing after completion 5
• Maintain the same intervals between remaining doses as the original schedule 5